All that rhetoric to the effect of "they're not fans of it and the way they talk about it, it's like they think others aren't either" ignores that it's likely nothing to do with being enamored or not with the original concept: "Pretenders with opening shells" is a pricey mess to actually execute (financially) and sell.
It's like bundling everyone with a trailer. So much of the budget is immediately used up making plastic shells big enough to house the inner robot; the inner robot will need to be simplified to hell and back both as a result of having a pittance of a budget left over and as a result of needing to fit inside the shell. On top of all of that, what do you do with these shell molds? They're not going to have the same tooling versatility as any other tooling (Metalhawk and Bludgeon make use of existing tooling, and just look at how many ways they've reused the Skullgrin base). There's a reason the one time it's been done in the last 20 years has been with tiny shells with all of 2 POA and similarly tiny basically one-step inner robots. So, however fondly I myself remember the originals (I wish we'd have gotten a Finback, damn it), if I were on the design team I'd find another way to bring them into the line too.
I'm fine with the recent attempts at blending the shell and the inner robot look, although perhaps we could lean a bit further on the shell look since the inner robots tend to be blocky and generic. (Also, if the baseline had been Deluxes, Bomb-Burst could have been even better, and Ignaus could have had more ways to not look like he's doing an exercise roller workout with a helmet on).
I do wish they came with alternate inner-robot heads, though; saw a digibash of Skullgrin that looked great.